Fire and Ice
by wild-minds-think-alike
Summary: Sent from Gehenna, a brother and sister have been sent on a mission. Watch Rin Okumura and tell his father how he is progressing. However, one of them may have other plans. Ones that will involve putting one of his friends in danger.
1. Chapter 1

Rin Okumura leaned back against a wall and closed his eyes, soaking in the rays of late-afternoon sunlight. **Rin, whatcha' doin'?**

"Oh, not much Kuro." The cat-sith jumped on his master's shoulder and rubbed against him.

**Wanna' play?**

"Not now, I'm just relaxing." Unknown to him, someone was watching him far off. They were holding a shining spear that had the point aimed right at him. The unknown person kept one eye closed, aiming so that, if they moved their arm just right, the point would enter right through Rin's right temple. A clean and perfect shot. His arm slightly pulled back...

"Nii-san!" The person turned around and saw someone else standing behind him. She was glaring at him and he put the spear down.

"You know what Ojisan said, we're only supposed to watch him, not kill him."

"Ch' I know that. I just testing a theory of mine." He gaze shifted back over to Satans' son, Rin Okumura. "He doesn't seem to notice much around him.." He muttered under his breath. His sister stood next to him now, her fire-colored eyes shining.

"He doesn't seem that interesting, I don't understand why we have to watch him." Her brother sighed as he, yet again, had to explain it to his sister.

"We are here to watch him because of what happened a few weeks ago." Eyes the color of warm flames met the icy snow colored ones of the older sibling.

"Oh, you mean when he went berserk?" she asked, as she went back to watching the young teen.

"Yes, when he went berserk and showed his flames to his classmates. Though, really I'm surprised no one has tried to kill him yet. That Ryuji Suguro guy seemed to be the type to kill or harm anything to do with demons and or satan.." His younger sister looked back at her brother

"Nii-san, you think to much. One day you're gonna' burst a vein," Kori growled and swatted at his sister. She jumped away with a slight swirl, her soft yellow dress spinning around her knees. "Nii-san, since this is your mission, you do it. I'll go home. Oh and don't let them find out!" Moeru turned around, a small dragon-like tail slipping out from underneath her dress. She cut her thumb and let the single drop of blood fall to the earth. A small box appeared where the blood hit the earth. She climbed into the box, waved good bye to her bother, and disappeared back to Gehenna.

"Damn Imouto, leaving me alone to do this..."

_Damn Kori, he thinks he's so high and mighty just because he's older than me! He was only asked to watch that Okumura jerk because he's good at surveillance! There's more important things than that! _Moeru 'hmph'ed and sank into her squashy arm-chair. _All we need to do is make sure that he can control his flames to Ojisan's specifications. There are other ways to do that that don't involve staking him out every minute of the day. And I have to wait twice as long for Nii-san to get back since he's in Assiah and I'm in Gehenna! It's not fair!_

An idea dawned on her and she smiled evilly, revealing her sharp teeth. _That's not a bad idea. Plus, if I take care of Okumura-san, then Nii-san will have more time to play with me!_ She pulled a small bell out of her purse and rang it. A puff of smoke poofed in front of her, and when it dissipated, it showed a byakko, quite similar to the ones Izumo was able to summon.

**What is your command Moeru-sama?** Moeru pulled out a pad of paper and a pencil and began writing.

"I need you to gather these ingredients for me. There's a potion I need to brew and it has to be done by tomorrow. Then I need you to collect small articles of clothing from each of these two." She pulled out two pictures and taped them to the back of the paper she had finished writing on. She ripped the page out of her notebook and tucked it into the byakko's collar. "Oh yeah, and I need these things in three Assiah hours, so you'd better not keep me waiting."

**Understood.** The byakko made an equivalent to a bow and disappeared. Moeru smiled and put an open hand in front of her face. A small red flame appeared and danced on her palm, lighting up her face with the warm glow.

_This will be fun._

Back in Assiah, Izumo Kamiki was studying with Paku in their dorm room. The young byakko was eager to do its first mission out of Gehenna. It was extra careful to be quiet and unseen by the two girls studying. Kage was its name, young mistress named him that when he turn 100 years old. That's still a pup in byakko standards. Once Kage was sure the human girls wouldn't notice him, he darted out and pulled three strains from the purple one's head and tore a small piece of her uniform off. It was the edge of the skirt, no one would notice it. He smirked, one down, one more to do. He disappeared before they could notice.

"Ouch! The hell was that?" Kage heard from down the hall.

"Izumo are you okay?" a kind, gentle voice asked.

"Yeah, must have pulled some hair out, when I was scratching my head.."

_Delayed reaction,_ Kage thought. As he entered the last dorm, the last part of his mission, he was stopped by something grabbing onto his neck and throwing him against the wall. He disappeared before a spear of ice could hit him. _Moeru-sama will not be pleased. _

Kori stood up from his crouched position. The sound of a door being opened, ringed in his ears. A pair of blue eyes meet his ice-snow colored ones, and blinked. _Okumura Yukio younger twin to Okumura Rin. . . Shit_

"Who are you?" Yukio asked. While Kori was one of the best surveyors in all of Gehenna, it didn't help his stature that he looked the age of a nine-year-old human boy.

"None of your business!" Kori snapped. He found in these situations that it was best to act like most humans saw him, a little kid. Yukio shook his head and grabbed him by the arm. "Hey! What are you doing? Let go of me!"

"No, you're heading to the main office. I don't know how you got here, but I'm sure your mother won't be too pleased that you wandered this far." Kori racked his brains, trying to think of a way to escape this predicament. Kage hadn't left the building, he had just disappeared from sight when Kori had tried to hit him. Said byakko was looking at his mistress's brother and was pondering what to do.

_Moeru-sama's instructions were very clear. Get the items and come back within three Assiah hours. But what about the young master?_ As he thought about this, Yukio was getting closer to the door. _I've got it, when I pull the hairs from the Okumura boy, it will attract his brother, and that will allow young master to escape!_ With this thought in his head, he swiftly whooshed off to where Rin was. He found said boy brushing his teeth. The byakko very carefully snuck up on him, but at the last moment, Rin saw a reflection of the fox-demon in the window.

"Hey!" He whipped around and faced Kage.**  
><strong>  
><em>Rats. Guess it's just an attack then.<em> He snarled and set upon Rin. Yukio was almost outside with the still-struggling Kori when he heard a blood-curling scream.

"Nii-san!" Yukio forgot about the little boy and ran back into the dorm where he saw the Byakko, he quickly grabbed his guns and fired, making sure not to hit his brother. The byakko quickly let go of Rin's arm and flew towards Yukio. Kage opened his mouth wide and was about to bite down on Yukios' arm when Kori appeared.

"Stop right now! Don't you dare harm them anymore!" Kori yelled, his eyes flashing, luckily the two twins didn't notice that. Kage stopped and stared at Kori, he shook his head. "Leave now..." Kori said in a dangerously low voice. Kage trembled for a moment, then quickly made made a bee-line away, before young master could do anything to him.

"Nii-san! Are you alright?" Yukio asked.

"Yeah, I'm fine, that thing just attacked me out of nowhere. Looks like it tore a piece out of my sleeve too. Felt like it pulled out a few hairs, but other than that I'm fine." In the midst of all the chaos, Kori disappeared into the shadows.

"Alright you, let's take you to the office and- huh?" When Yukio turned to get Kori, he found that the child had disappeared."Where did he go?"

"Where'd who go?" Rin asked.

"This kid that I had, he must have run off in all of the commotion."

Kuro, who was outside at the time, saw a small boy running out of the dorm. He jumped down in the boy's path. **Who are you? **Kori jumped when the cat-sith appeared in front of him.

"None of your business cat." He turned to move, only to find nothing but dense trees behind him. _Damn, I wish that cousin was here right now... Where is Mephisto-san any way?_ Kuro jumped in front of him again and sat there, despite how small he was at the moment.

**Why are you here?** Kori grimaced and tried to get around him.

"I said it's none of your business cat!" Kuro once again blocked his path, this time getting in the way of his legs.

**It is, why are you here?** With a growl, Kori kicked Kuro hard, sending him flying into the nearest tree. A pained yowl filled the night air as Kuro cried out in his mind.

**Rin! Rin! The bad person hurt me! RIN! IT HURTS RIN!** Kori gasped when he realized what he had just done.

_Damnit, I just meant to send him a few feet, not smash him into a tree! _He was about to run, when a gigantic bird with a white top-hat came out of nowhere. "What the-?" The bird grabbed him, pulling him out of sight.

Inside**  
><strong>  
>Yukio was putting his guns away while Rin watched his healing wounds. <strong>Rin! Rin!<strong>Rin tensed when he heard this.

"Kuro?"

"What was that?" Yukio asked.

**The bad person hurt me! RIN! IT HURTS! RIN!**

"Something's wrong with Kuro!" He raced out of the room, Yukio chasing after him. When Rin found Kuro, his cat-sith familiar was in the hollow of a tree, covered in what could only be his own blood.

"Kuro! Hey, hey are you okay?" He carefully picked him up and held him close. "Shhh, shhh, it's okay, I got you now...Shhh..." Kuro whimpered in pain.

**Rin the bad person hurt me Rin! He hurt me!**Rin stopped rocking him and looked around with narrowed eyes, trying to find the person who would have harmed HIS kuro.

"What did he do?" Rin asked, Yukio was asking what happened, but Rin glared at him, and that shut Yukio up for the moment.

**He kicked hard!**

Rin blinked and growled. "No normal human could have done that! It bet it was a demon of some sort!" When Kuro was just about to pass out he handed him to Yukio "Fix him, I'll go look around." Yukio pushed his glasses back up his nose and nodded.

Kori smiled and his small, pointed teeth were seen "Hello cousin, I thought for a moment you'd forgotten about me." Mephisto smiled haughtily at his younger cousin.

"I apologize, I was wrapped up with some business and couldn't get away until just now. I see that you look as small as ever." Kori frowned at Mephisto. His older cousin's face darkened slightly. "I also see that you've managed to deal my otouto's familiar quite a blow." Kori crossed his arms.

"The cat-sith wouldn't get out of my way. I didn't mean to his him so hard, but that's what happens if you don't listen to me." Mephisto grabbed Kori by the shoulder and held him firmly.

"Now listen closely my dear younger cousin. Just because you're family doesn't mean I won't harm you. If you're here because of some mission from father, then leave. If not," Mephisto smiled, it seemed as though his smile would crack his face in half, "then welcome to True Cross Academy. You'll be a new student in the Cram School for exorcists. Now now, I already know you want nothing to do with us Exorcists, but this way I can keep an eye on you and you can still watch Otouto. How does that sound?"

Kori smirked "Sounds good to me."


	2. Chapter 2

Rin watched anxiously as Yukio examined Kuro. "Well, how is he?" Yukio shook his head.

"Whoever or whatever did this certainly was strong. Otherwise Kuro couldn't have gotten hurt so badly. He's got multiple lacerations, quite a few bruises, and a broken leg." He looked Rin in the eye seriously. "Rin, I know you're not gonna' like hearing this, but I'm going to have to re-break Kuro's leg." Rin immediately went on the defensive for his familiar.

"WHAT? WHY?" Yukio adjusted his glasses.

"If I don't break his leg, when it heals, it could be completely out of form and impede his movements." Rin thought this over for a moment.

"Okay, but on one condition." Yukio asked what that was. "I'll be the one to do it." Yukio was surprised by this, but when he saw the determined look on his brother's face he nodded. When Rin placed his hands on Kuro, his familiar stirred slightly and opened his eyes a bit.

**R-rin?**

"Kuro, listen to me, I'm going to have to hurt you. But after I do, it will help you heal. Are you okay with that?"

**Yes, I trust you Rin.**With these thought-spoken words, Rin gently took hold of Kuro's broken front leg. Had his familiar always seemed this small, this fragile? It broke easier than he had expected, with his demon strength Kuro's leg re-broke with a snap like a breaking twig. Kuro cried out in pain as the bone crunched. Yukio immediately began setting the limb. Once that was done, he applied medicines and bandages to all of the other wounds until all of Kuro's wounds were bandaged.

"He'll still need to be treated, but he'll be fine."

Rin nodded in understanding. Once Yukio was done Rin picked up Kuro close to him. His warmth made Kuro sleepy and soon he was sound asleep in Rin's arms. Rin walked slowly over to his bed, and lay down, making sure that Kuro right beside him. Yukio watched them fall asleep, and picked up his phone when he felt it vibrating softly in his pocket.

"Hello, Okumura speaking." The deep, yet light, undertone of Mephisto's voice sounded into his ear.

"Ah..Okumura-san I thought you'd never pick up. You'll have a new student tomorrow named Sikora Kori. You might need to watch out for him, he isn't quite human you see..." Yukio told him that it was alright and hung up. Not even 30 minutes later, he too was sound asleep.

* * *

><p>A dark figure walked into the twins' dorm and headed over to Rin's bed. The figure placed a golden pill on Kuro's tongue. Once Kuro had swallowed it, the figure left.<p>

"Good night Kuro-chan," a girlish voice whispered into the darkness, "and don't remember the person that harmed you please. It would leave us with some unpleasant problems to take care of."

Back in Gehenna

Moeru was sitting at a small table, eating a slice of cake, when Kage appeared. "Mistress, I brought you the items you asked for." Moeru quickly left her cake and jumped on Kage, hugging him like she might hug a teddy bear.

"Good job Kage-chan!" She took the items from him and went to work. She put the ingredients into a mini cauldron and lit a fire under it from her own hand. Once it was bubbling nicely, she pulled out two dolls. On each doll she put respective clothing pieces and hairs. She began chanting over the dolls and blue smoke swirled from the cauldron. The smoke surrounded the dolls in a small vortex. When the smoke cleared, both dolls were softly glowing. Moeru carefully placed both dolls next to each other so their tiny hands were touching. With a dropper, she carefully put a few drops of potion on each doll. The glow subsided, leaving them looking totally ordinary. Just as she had finished putting everything away, Kori appeared.

"Welcome back Onii-san, how was it in Assiah?" Her brother said nothing, but handed her what seemed to be a girl's school uniform.

"Hmm? Whats this for Nii-san," Moeru asked, looking at the uniform.

"It's a uniform for the True Cross Academy, you'll be in the school where Okumura Rin goes to school during the day, and I will be going to Cram School where Okumura Rin goes to learn how to become an Exorcist." Moeru's brother's eyes were glowing white like the hottest ember from a fire, but Moeru knew that, if she could feel her brothers eyes, they wouldn't be hot, but freezing cold.

"Oh, so I'm going to the normal human school, and you the Exorcist school?" Moeru asked as she looked at the uniform against her skin. The color would make her look darker and her brother whiter.

"Yes, it would be weird having two new students at the same time in the cram school, I'm sorry Imouto." He hugged his sister close, inhaling the smell of crisp autumn leaves that seemed to be stuck to Moeru no matter what she tried to cover it with. "If I see Kage again, Imouto, or whatever you've made while I've was gone, your not ever gonna' get a hug from me again." He stood up, "Now, I must go, Cram School begins in a few hours in Assiah," Kori kissed her top of her head and left. Moeru touched where her brother kissed her, it was cold with little picks of ice that melted away faster then she wanted them to.

_Nii-san may not be too happy about what I've done now, but I know it'll make his job a whole lot easier. Though, I don't know how Nii-san expects us both to fit into a high school so well when we both look like grade-schoolers._


End file.
